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No. 689,226. Patented D80. I7, mm.

T. o. aulsf & J. rynosAul WITNESSES: INV'EN 0R5 T I ATTORNEY- mg mam: PEYERS m. mom-Luna. wunmmnu. n. o.

n Patented De'c. I7, lam. T. 0. (mm a T. HOGAN.

TENSIDN DEVICE FOR SEWlNG IACHINES.

(.lpplicltion filed In. 10, 189?.)

(In low.)

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' To all whom it may concern.-

*dinary construction, a being the base-plate UNITED STATES" PATENT OFFICE.

THORVALD O. QUIST, OF NEW YORK, N. Y., AND JAMES T. IIOGAN, OF JERSEY'OITY, NEW JERSEY, ASSIGNORS TO THE NATIONAL MACHINE COMPANY, TROY, NEW YORK,

TENSION DEVICE "FOR A CORPORATION OF NEW YORK.

SEWING-MACHINES.

SPEOIFICATION'forming part of Letters Patent No. 689,226, dated December 17,1901- Application filed lilai'ch 10, 1898.

Be it known that we, THORVALD O. QUIsT, residing in the borough of Brooklyn, city and State of New York, and JAMES T. HOGAN, residing in Jersey City, Hudson county, and State of New Jersey, citizens of the United States, have invented a new and useful Improvement in Tension Devices for Sewing. Machines, of which the following, is a specification.

We will describe a machine embodying our improvement and then point out the novel features in the claims.

In the accompanying drawings, Figure l is a front elevation of a sewingmachine embodying our improvement. Fig. 2 is a top view of a portion of the same upon an enlarged scale. Fig. 3 is a transverse section of certain parts and an elevation of others upon substantially the same scale as Fig. 2. Fig. 4 is an enlarged inverted plan of a cam comprised in the machine.

Similar letters of reference designate corresponding parts in all the views of the drawmgs.

A designates a sewing-machine head of orand a the arm. This sewing-machine is of that kind in which are stitched bnttonholes having two parallel rows of side stitches arranged upon opposite sides of the buttonholeopening and two sets of barring-stitches crossing the ends of the opening and the two rows of side stitches. It has been found that if the same thread tension is employed for making the barring-stitches as for making the two rows of side stitches a puckering of the fabric in which the buttonhole is formed will result. We therefore wish to provide in a simple manner for lessening the tension during the formation of the barring-stitches relatively to that which is employed during the formation of the side rows of stitches. Au important'advantage resulting from the use of this tension device is that the shuttlethread is mainly used to form the side rowsof stitches, whilethe needle-thread is mainly used to form the barring-stitches. When the needle thread is coarser than the shuttle- Serial No. 673,312. (No model.)

side stitches of relatively finer'thread-is produced, While at the same time the increased strengthof the coarser thread is obtained in the bars of the buttonhole.

Bdesignates a hand-wheel upon the main shaft. In the present instance this is provided with a projection Z2 upon that side which is toward the arm of the sewing-machine head, and that projection cooperates with a lever C, comprised in a stop mechan- D designates a tension device of any appro priate form which will constantly act upon the thread passing through the needle.

E designates another tension device for operating upon the thread. As here shown, this tension device consists of two disks 6' e between which the thread passes. The upper disk'c is impelled toward the other by a spring e surrounding a spindle 6, extending from the lower disk and receiving the upper disk upon it. A nut applied to the spindle may serve to adjust the force of the spring. The tension of this device is preferably greater when it is in operation than the tension of the device on the thread of the shuttle of the machine.

F designates a lever fulcrumed to a pin or screw f. As here shown,this pin f and the spindle e are supported upon a plate G, that is afiixedby a screw g to the arm a of the sewing-machine. The upper end of the lever is somewhat pointed, so that it may enter between the plates 6 e for the purpose of separating the former from the latter. Normally sewing-machine head an incline f, which co' operates with a lever-II at such timesas the latter occupies an appropriate position.

It is intended that the tension D should 0p.- erate continuously, but that the tension E should only operate periodically and during the sewing of the two side rows of stitches.

The lever H is fulcrumed by a screw or pin it to the arm of the sewing-machine head. With it is pivotally connected by a pin or screw h one end of a rod I, which extends down through the base-plate a of the sew-- ing-machine head, where it is pivotally connected to a lever i, that is fulcrumed by a pin or screw t to a bracket extending from the under side'of the said bed-plate. Aspring i surrounds the rod I between the bed-plate and a collar 2, which is fastened to said rod, thus giving an upward tendency to the rod, and consequently to the levers H and 1'. Adjacent to the lever t' is a cam J, with which a followert'", attached to the lever i, cooperates. Thecam isa rim-cam and is providedwith a notch into which the follower 2' may rise when free to he moved upwardly by the spring 2'.

When the lever II is moved upward, it will cooperate with the incline f of the lever F to move the upper endof the lever F inward for the purpose of releasing the thread from the tension device E. When the lever H is lowered, the lever F willbe free to move out wardagain. It is evident that the greater the distance the rod K is from the fulcrum lot lever L the amplitude of the jogging move- .ment of the needle-bar will be greater, and

consequently the barring-stitches will be longer than the side stitches. The lever H in this example of our improvement has the additional function of moving a rod K to different points lengthwiseof a lever L, which isfulcrumed on a shaft or fulcrum Z in the arm of the sewing-machine head. The office of the rod K is .to oscillate a frame carryihg the needle-bar for the purpose of positioning the needle for difierent stitches. When the lever H raises the rod K toward the upper end of the lever L, it adjusts it for the tension of the barring-stitches of a buttonhole, and consequently it is at this time that the tension E will be rendered inoperative by said lever H. The thread of the needle cooperateswith the thread of the shuttle to form stitches in the usual manner. The shuttle is operatedfrom the main shaft by the usual mechanism, and the usual tension device is provided for the thread carried thereby. The tension of the device E should preferably be greater when it is acting on the needle-thread than the tension of the device provided for the shuttle-thread.

It is desirable to free the thread from the ehiet of the tension device E when the sewing-machine is stopped, and consequently we combine with the lever F a bell-cranklever M, f-ulcrnmed by a pin or screw m to a bracket m, extending from the arm of the sewing-mathe leverlG. As here shown, the lever C is provided with a screw-eye n, and the rod N is provided with a hook it, suitable for engagement with the said eye it. The other end of the rod N passes into a screw-clamp n which engages-with a slide portion of the bellcrank lever, so that it may be adjusted toward and from the fulcrum of the latter. \Vhen the sewing-machine stops, the upper end of the lever 0 moves to the right, and thus swings forwardly that end of the bell-crank lever M which crosses the lever F, and consequently't'orces the upper end of the lever F inwardly, so that it will raise the upper disk of the tension device and relieve the thread, and when lever C is movedto the left in starting the machine the bell-crank lever M is moved outof contact with lever F, and the pinching effect of thedisks e e forces the upper end of the lever F out from between said disks, th usapplying the tension to the thread.

The operation of the machine,briefly stated,

isv as follows: The machine when it is started sews one of the side rows of stitches at which time the tension device E is in operation upon the needle'thread. The elfect of the stronger tension upon the needle-threadis to pull the thread out of the shuttle, thereby mainly using the thread of the shuttle to form, the stitches at the sides of the buttonhole. The needle-thread during thisoperation lies along the edge of the buttonhole, and the shuttlethread will be whipped over it, so that the effect obtained along the side of the buttonhole is thatof a purl-stitch. When. the tension device E is operated torelieve the tension upon the needle-thread, which is when the barringrstitches are to be formed, the machine will stitch with the tension device D operating on the needle-thread. As the tension of this device is not asstrong. as the tension on the shuttle-thread, the needlethread'will mainly be used in the bars, the shuttle thread acting merely to lock the stitches. The shuttle-thread will therefore be saved to a great extent, in making, these long stitches, thus reducing the necessity of stoppages for supplying shuttle-thread.

What we claim as new,and desire to secure by Letters Patent, is

1. In a machine for making buttonholes v which have side rows of stitches and barring-' stitches, the combination of a work-support and means to feed the same lengthwise of a buttonhole, a needle and concomitant parts, means for producing a vibratoryv movement of the needle to form the side stitches and a vibratory movement of greater amplitude to form the barring-stitches, a tension device for the needle-threadand a tension-controller therefor connected to and operated by the means which vary the amplitude of vibration of the needle.

2. In a machine for making buttonholes which have side rows of stitches and barringstitches, the combination of a work-support and means to feed the same lengthwise of a buttonhole, a needle and concomitant parts, means for producing a vibratory movement of the needle to form the side stitches and a vibratory movement of greater amplitude to form the barring-stitches, a tension device for the needle-thread, means comprising a cam to vary the amplitude of vibration of the needle, and a tension-controller connected to and operated by said means to change the tension on the needle-thread when the amplitilde of vibration of the needle is increased.

3. In a machine for making buttonholes which have side rows of stitches and barringstitches the combination of a needle and concomitant parts, a work support, means for producing a relative jogging movement between the needle and work-support for forming the side rows of stitches and a relative jogging movement of greater amplitude between the needle and work-support for forming the barring-stitches, a tension device for the needle-thread, means for changing the tension on the needle-thread and means for simultaneously controlling the means for producing the difierent relative jogging move- 'ments between the needle and work-support and the means for changing the tension on the needle-thread for the sewing of one set of stitches.

4. In a machine for making buttonholes which have side rows of stitches and barringstitches, the combination with a needle and concomitant parts, of means to vibrate the needle, a tension device for the needle-thread,

, alever to vary the amplitude of vibration of the needle and at the same time to operate the tension device to change the tension on the needle-thread, and means to actuate said lever, substantially as described.

5. In asewing-machine for making buttonholes which have side rows of stitches and barring-stitches, the combination of a needle and concomitant parts,a work-support,means for producing a relative jogging movement between the needle and work-support to form the side rows of. stitches and a relative movement of greater amplitude between the needle and work-support for forming the barringstitches, and comprising a lever H, a tension device for the needle-thread, a lever]? adapted to be engaged by the lever H, and a cam for operating the lever H.

6. In a sewing-machine the combination of a needle and concomitant parts, a tension device for the needle-thread, a protuberance on the main driving-shaft, a stop mechanism comprising a lever to frictionally engage said protuberance to stop the machine, a second lever adapted to engage the tension device to change the tension, and a third lever intermediate the first and second named levers and actuated by the former to operate the tension-changing lever when the machine is stopped, substantially as described.

7. .In a sewing machine the combination of a needleiand concomitantparts, a tension device for the needle-thread, a protuberance on the main driving-shaft, a stop mechanism comprising a lever to frictionally engage said protuberance to stop the machine, a bellcrank lever connected to and actuated by said first-named lever, and a third lever actuated by said bell-crank lever to engage the tension device and change the tension on the thread when the machine is stopped, sub stantially as described.

In testimony whereof we have signed our names to this specification in the presence of two subscribing witnesses.

THORVALD O. QUIST. JAMES T. HOGAN.

Witnesses:

ORVILLETT ToBEY, JOHN J. SHAW. 

